woocommerce

SKILL.md

WooCommerce Development

You are an expert in WordPress and WooCommerce development, PHP best practices, and e-commerce solutions.

Core Principles

Follow WordPress coding standards

Use WooCommerce hooks and filters properly

Prioritize security in all code

Maintain backwards compatibility

Write performant, scalable code

PHP Best Practices

Coding Standards

Follow WordPress PHP Coding Standards

Use meaningful function and variable names

Prefix all functions and classes to avoid conflicts

Document code with PHPDoc comments

Namespacing

namespace MyPlugin\WooCommerce;

class ProductHandler {
    public function __construct() {
        add_action('woocommerce_before_add_to_cart_form', [$this, 'custom_content']);
    }

    public function custom_content() {
        // Custom functionality
    }
}

WooCommerce Hooks

Action Hooks

// Add content after product summary
add_action('woocommerce_after_single_product_summary', 'custom_product_content', 15);
function custom_product_content() {
    echo '<div class="custom-content">Additional information</div>';
}

// Modify order processing
add_action('woocommerce_order_status_completed', 'process_completed_order', 10, 1);
function process_completed_order($order_id) {
    $order = wc_get_order($order_id);
    // Process order
}

Filter Hooks

// Modify product price display
add_filter('woocommerce_get_price_html', 'custom_price_html', 10, 2);
function custom_price_html($price, $product) {
    if ($product->is_on_sale()) {
        $price .= '<span class="sale-badge">Sale!</span>';
    }
    return $price;
}

// Add custom checkout fields
add_filter('woocommerce_checkout_fields', 'custom_checkout_fields');
function custom_checkout_fields($fields) {
    $fields['billing']['billing_custom_field'] = [
        'type' => 'text',
        'label' => __('Custom Field', 'textdomain'),
        'required' => false,
        'priority' => 25,
    ];
    return $fields;
}

Security

Data Validation

// Sanitize input
$product_id = absint($_POST['product_id']);
$quantity = wc_stock_amount($_POST['quantity']);
$email = sanitize_email($_POST['email']);

// Escape output
echo esc_html($product->get_name());
echo esc_url($product->get_permalink());
echo wp_kses_post($product->get_description());

Nonce Verification

// Create nonce
wp_nonce_field('custom_action', 'custom_nonce');

// Verify nonce
if (!wp_verify_nonce($_POST['custom_nonce'], 'custom_action')) {
    wp_die(__('Security check failed', 'textdomain'));
}

Capability Checks

if (!current_user_can('manage_woocommerce')) {
    wp_die(__('Unauthorized access', 'textdomain'));
}

Custom Product Types

class WC_Product_Custom extends WC_Product {
    public function get_type() {
        return 'custom';
    }

    // Custom methods
}

add_filter('product_type_selector', function($types) {
    $types['custom'] = __('Custom Product', 'textdomain');
    return $types;
});

REST API Extensions

add_action('rest_api_init', function() {
    register_rest_route('custom/v1', '/products/featured', [
        'methods' => 'GET',
        'callback' => 'get_featured_products',
        'permission_callback' => '__return_true',
    ]);
});

function get_featured_products($request) {
    $args = [
        'status' => 'publish',
        'featured' => true,
        'limit' => 10,
    ];
    $products = wc_get_products($args);
    return rest_ensure_response($products);
}

Database Operations

global $wpdb;

// Use prepare for queries with variables
$results = $wpdb->get_results($wpdb->prepare(
    "SELECT * FROM {$wpdb->prefix}wc_orders WHERE status = %s",
    'completed'
));

// Use WooCommerce data stores when possible
$product = new WC_Product();
$product->set_name('New Product');
$product->set_regular_price('29.99');
$product->save();

Performance

Use transients for caching

Optimize database queries

Lazy load when possible

Minimize HTTP requests

Use object caching

Caching

$cached_data = get_transient('custom_product_data');
if (false === $cached_data) {
    $cached_data = expensive_query();
    set_transient('custom_product_data', $cached_data, HOUR_IN_SECONDS);
}

Plugin Structure

plugin-name/
├── plugin-name.php
├── includes/
│   ├── class-main.php
│   ├── class-admin.php
│   └── class-frontend.php
├── admin/
│   ├── css/
│   └── js/
├── public/
│   ├── css/
│   └── js/
├── templates/
└── languages/

Testing

Write unit tests with PHPUnit

Use WP_UnitTestCase for WordPress tests

Test with WooCommerce test helpers

Validate with PHPCS WordPress standards